When loading or unloading a truck parked at a loading dock, it is generally a safe practice to help restrain the truck from accidentally moving too far away from the dock. This is typically accomplished by a hook-style vehicle restraint that engages what is often referred to in the industry as an ICC bar or a Rear Impact Guard (RIG) of a truck. An ICC bar or RIG is a bar or beam that extends horizontally across the rear of a truck, below the truck bed. Its primary purpose is to help prevent an automobile from under-riding the truck in a rear-end collision.
An ICC bar, however, also provides a convenient structure for a hook-style restraint to reach up in front of the bar to obstruct the bar's movement away from the dock. An example vehicle restraint may be stored behind the dock face, and extends and retracts hydraulically to firmly capture or release an ICC bar via a hook. Typically, hydraulic pressure is used to operate the restraint. However, hydraulic pressure substantially resists longitudinal movement of the hook. While there are benefits to restraints that store behind the dock face, using a hydraulic cylinder or other actuator to resist some, or all of to pullout forces of the vehicle is not ideal.